1. Field of Invention
The present invention relates to the field of flow control. More specifically, the invention relates to a device and method for controlling the flow into a conduit through a sand face completion.
2. Related Art
Oil companies are continually improving their recovery systems to produce oil and gas more efficiently and economically from sources that are continually more difficult to exploit, without significantly increasing the cost to the consumer. Two relatively recent developments to increase production are the use of deviated and/or multilateral wells and intelligent completions. In multilateral wells a number of deviated wells are drilled from a main borehole. Intelligent completions generally include downhole monitoring devices and control devices that are remotely actuatable from the surface.
A wellbore may pass through various hydrocarbon bearing zones or may extend through a single zone for a long distance. One manner to increase the production of the well is to perforate the well in a number of different locations, either in the same hydrocarbon bearing zone or in different hydrocarbon bearing zones, to increase the flow of hydrocarbons into the well. One problem associated with producing from a well in this manner relates to the control of the flow of fluids from the well and to the management of the reservoir. For example, in a well producing from a number of separate zones, or lateral branches in a multilateral well, in which one zone has a higher pressure than another zone, the higher pressure zone may produce into the lower pressure zone rather than to the surface. Similarly, in a horizontal well that extends through a single zone, perforations near the xe2x80x9cheelxe2x80x9d of the wellxe2x80x94nearer the surfacexe2x80x94may begin to produce water before those perforations near the xe2x80x9ctoexe2x80x9d of the well. The production of water near the heel reduces the overall production from the well. Likewise, gas coning may reduce the overall production from the well.
A manner of alleviating such problems may be to insert a production tubing into the well, isolate each of the perforations or lateral branches with packers, and control the flow of fluids into or through the tubing. Note that throttling may also be desired in wells having a single perforated production zone. However, typical flow control systems provide for either on or off flow control with no provision for throttling of the flow. To fully control the reservoir and flow as needed to alleviate the above-described problems, the flow must be throttled. A number of devices have been developed or suggested to provide this throttling.
Specifically, the prior devices are typically either wireline retrievable valves, such as those that are set within the side pocket of a mandrel, or tubing retrievable valves that are affixed to the tubing string. An example of a wireline retrievable valve is shown in U.S. patent application Ser. No. 08/912,150, by Ronald E. Pringle entitled xe2x80x9cVariable Orifice Gas Lift Valve for High Flow Rates with Detachable Power Source and Method of Using Samexe2x80x9d that was filed Aug. 15, 1997, and which is hereby incorporated herein by reference. The variable orifice valve shown in that application is selectively positionable in the offset bore of a side pocket mandrel and provides for variable flow control of fluids into the tubing.
A typical tubing retrievable valve is the standard xe2x80x9csliding sleevexe2x80x9d valve, although other types of valves such as ball valves, flapper valves, and the like may also be used. In a sliding sleeve valve, a sleeve having orifices radially therethrough is positioned in the tubing. The sleeve is movable between an open position, in which the sleeve orifices are aligned with orifices extending through the wall of the tubing to allow flow into the tubing, and a closed position, in which the orifices are not aligned and fluid cannot flow into the tubing.
Other types of downhole valves include the valves shown in U.S. patent application Ser. No. 09/243,401, by David L. Malone, entitled xe2x80x9cValves for Use in Wellsxe2x80x9d that was filed Feb. 1, 1999, and U.S. patent application Ser. No. 09/325,474, entitled xe2x80x9cApparatus and Method for Controlling Fluid Flow in a Wellborexe2x80x9d by Ronald E. Pringle et al., that was filed Jun. 3, 1999. In general, the valve has valve covers that provide a seal around the periphery of the cover and the orifice through the tubing.
Often, completion equipment includes sand control equipment, which are used to limit the production of sand from a formation. Sand production can damage the well and significantly reduce the production and life of the well. The flow of production fluid may be insufficient to lift the sand from the well resulting in build-up of sand in the well. Sand produced to the surface is a waste product requiring disposal. During production of the sand, the sand acts as an abrasive wearing and eroding downhole components, which may damage downhole tools. Further, production of sand may damage the formation creating voids behind the casing which may result in buckling of or other damage to the casing.
Consequently, various methods and devices for reducing or eliminating sand production have been developed. Gravel packing of the formation is a primary method for controlling the sand production. However, other sand control mechanisms may also be used. Although there are variations, gravel packing essentially involves placing a sand screen around the section of the production string containing the production inlets. This section of the production string is aligned with the perforations. A slurry of gravel and a viscous transport fluid is pumped through the tubing into the formation and the annulus between the sand screen and the casing. The deposited gravel holds the sand in place preventing the sand from flowing to the production tubing while allowing the production fluids to be produced therethrough.
In multi-zone wells or in a well having multiple flow sections, flow control devices (such as the a ones described above) may be used to control fluid flow through orifices formed between the tubing bore and an annulus between the tubing and casing. However, if sand face completion equipment including gravel packing is installed, then the annulus is typically filled, which makes it difficult to position such flow control devices in the proximity of sand control equipment. The formation fluid must first flow generally radially through the sand control device before flowing to the flow control device. One option is to install the flow control device inside a tubing bore in the proximity of the production zone. However, this reduces the available flow area for production flow. Thus, there remains a need for flow control devices that provide incremental choking of the flow and that may be used in sand control completion equipment.
In general, according to one embodiment, a method of controlling fluid flow in a sand control completion includes providing a flow path from a space defined inside a sand screen to a choked orifice. Further, one of at least an open position, closed position, and an intermediate position of the choked orifice is selected to control fluid flow.
In general, according to another embodiment, an apparatus for use in a wellbore having a tubing includes a flow control assembly having at least one orifice and a bore capable of communicating with a bore of the tubing. The flow control assembly includes at least one valve adapted to control fluid flow through the at least one orifice to the bore. The valve is adapted to be actuated between an open position, a closed position, and at least an intermediate position. A sand control assembly is coupled to the flow control assembly and includes a sand screen and a flow path defined inside the sand screen in fluid communication with the at least one orifice.
Other features and embodiments will become apparent from the following description, the drawings, and the claims.